Aircraft engine fluid system with shut-off valve

Abstract

An aircraft engine, has: a fluid system including a fluid circuit fluidly connecting a plurality of components to a source of a fluid, the fluid being flammable, a component of the plurality of components containing a volume of the fluid during normal operation; and a valve fluidly connected to the fluid circuit upstream of the component relative to a flow of the fluid towards the component, the valve having an open configuration fluidly connecting the source of the fluid to the component through the valve and a closed configuration in which the valve disconnects the source of the fluid from the component, the valve movable from the open configuration to the closed configuration in response to the component being subjected to a fire event.

The invention claimed is: 
     
       1. An aircraft engine, comprising:
 a fluid system including a fluid circuit fluidly connecting a plurality of components to a source of a fluid, the fluid being flammable, a component of the plurality of components containing a volume of the fluid during normal operation; and 
 a valve fluidly connected to the fluid circuit upstream of the component relative to a flow of the fluid towards the component, the valve having a valve inlet, a valve outlet, and a housing defining a valve seat located between the valve inlet and the valve outlet, the valve having a valve member and a deformable member engaged to the valve member, the valve having an open configuration in which the valve member is offset from the valve seat and in which the source of the fluid is fluidly connected to the component through the valve and a closed configuration in which the valve member abuts the valve seat and in which the valve disconnects the source of the fluid from the component, the valve movable from the open configuration to the closed configuration in response to the component being subjected to a fire event, 
 wherein the deformable member is in contact with the fluid, a shape of the deformable member being variable with a temperature variation of the fluid, the deformable member biasing the valve member against the valve seat to position the valve in the closed configuration when exposed to the fluid at a temperature above a temperature threshold. 
 
     
     
       2. The aircraft engine of  claim 1 , wherein the deformable member has a first shape and a second shape different than the first shape, the valve being in the open configuration when the deformable member is in the first shape and being in the closed configuration when the deformable member is in the second shape. 
     
     
       3. The aircraft engine of  claim 2 , wherein a length of the deformable member varies from the first shape to the second shape. 
     
     
       4. The aircraft engine of  claim 3 , wherein the length is greater in the second shape than in the first shape. 
     
     
       5. The aircraft engine of  claim 2 , wherein the deformable member biases the valve member against the valve seat in the second shape and maintains a gap between the valve member and the valve seat in the first shape. 
     
     
       6. The aircraft engine of  claim 2 , wherein the deformable member includes a shape-memory alloy, the valve being proximate to the component. 
     
     
       7. The aircraft engine of  claim 6 , wherein the deformable member is a rod helicoidally wounded about a longitudinal axis, the deformable member and the longitudinal axis being in-line with a line of the fluid circuit. 
     
     
       8. The aircraft engine of  claim 7 , wherein a force required to move the deformable member between the first shape and the second shape is greater than a pressure of the fluid times a surface area of a projection of the valve member on a plane normal to the longitudinal axis. 
     
     
       9. The aircraft engine of  claim 1 , comprising a low-pressure shaft drivingly engaged to a load, the low-pressure shaft drivingly engaged to a pump in fluid communication with the fluid circuit, a drive path from the load to the pump, the drive path devoid of a clutch between the load and the pump. 
     
     
       10. The aircraft engine of  claim 9 , wherein the component is an actuator. 
     
     
       11. A method of stopping a flow of a fluid to a component of a fluid system of an aircraft engine, the fluid being flammable, the method comprising:
 permitting fluid communication from a source of the fluid to the component through a valve located upstream of the component, the component containing a volume of the fluid during normal operation, the valve having a valve inlet, a valve outlet, and a housing defining a valve seat located between the valve inlet and the valve outlet, the valve having a valve member and a deformable member engaged to the valve member; and 
 upon the component being exposed to a fire event, blocking fluid communication from the source of the fluid to the component by closing the valve, the closing of the valve including contacting the deformable member with the fluid to deform the deformable member with heat of the fluid thereby biasing the valve member against the valve seat. 
 
     
     
       12. The method of  claim 11 , wherein the deformable member has a first shape in which the valve member is distanced from the valve seat and a second shape different than the first shape and in which the valve member is biased against the valve seat, the blocking of the fluid communication from the fluid source to the component includes deforming the deformable member with heat of the fluid from the first shape to the second shape. 
     
     
       13. The method of  claim 12 , wherein the deforming of the deformable member includes varying a length of the deformable member with the heat of the fluid. 
     
     
       14. The method of  claim 13 , wherein the varying of the length includes increasing the length. 
     
     
       15. The method of  claim 12 , wherein the deformable member is a rod helicoidally-wounded about a longitudinal axis, the rod made of a shape-memory alloy. 
     
     
       16. The method of  claim 15 , wherein the permitting of the fluid communication from the fluid source to the component includes flowing the fluid around the valve member. 
     
     
       17. The method of  claim 11 , comprising shutting down the aircraft engine and allowing a propeller of the aircraft engine to rotate by wind milling. 
     
     
       18. The method of  claim 17 , wherein the blocking of the fluid communication from the fluid source to the component with the valve includes resisting a pressure of the fluid driven by a pump drivingly engaged by the propeller. 
     
     
       19. The method of  claim 11 , wherein the blocking of the fluid communication from the fluid source to the component with the valve in response to the component being subjected to the fire event includes closing the valve when a temperature of the fluid is above a predetermined temperature, the predetermined temperate being above a maximal operating temperature of the fluid. 
     
     
       20. The method of  claim 11 , wherein the fluid is oil.